Print drier



PRINT DRIER 2 Sheets-Sheet l Filed March 13, 1963 In l/EHTOR Hei n rich Ger-STH- Nov. 15, i966 H. GERSTER 3,284,921

PRINT DRIER Filed March 13, 1965 2 Sheets-Sheet 2 /Fgi 2 M9 M9 H7 m5 04 M6 /05 InVEn-TOR Heim-Xd@ @erster ATTORNEYS Patented Nov. 15, 1966 3,284,921 PRINT DRIER Heinrich Gerster, Industriestr-asse 4, Bruchsal-Karlsdorf, Germany Filed Mar. 13, 1963, Ser. No. 264,857 Claims. (Cl. Sti-143) The present invention relates to an apparatus for drying photographic prints and enlargements and comprises a heating unit, a mirror-finished dry-plate which is adapted to be lifted off the heating unit, and a clamping frame with a drying cloth thereon which is pivotable relative to the dry-plate and adapted to be locked thereto.

In the conventional apparatus of this type the wet prints which are to be dried with a glossy finish are applied face down upon a mirror-finished dry-plate, while the latter is remove-d from the heating unit, and the prints are then pressed upon the dry-plate either mechanically by a special device or by hand by means of a roller squeegee. The dry-plate with the prints squeegeed thereon is then placed upon the surface of the heating unit and covered and clamped down by the drying cloth which is held within the clamping frame. These known apparatus have several disadvantages which prevent them frcm being employed for drying prints with very sensitive surfaces, especially color prints. Thus, for example, it is very undesirable that the prints after being squeegeed upon the `dry-plate do not remain clamped thereon while the dry-plate is being placed upon the heating unit, but have to be pressed again upon the dry-plate by pivoting the clamping frame and the drying cloth thereon after the dry-plate has been placed upon the heating surface. lt is a well-known fact that after parts of the prints have again separated from the chrome-plated surface of the dry-plate, the clamping effect of the clamping frame after being pivoted downwardly is alone not sufficient to press the prints again so tightly upon the dry-plate that they will finally have a perfect high-gloss finish. A further disadvantage of the known apparatus is that they require the length of the drying period of the prints to be carefully watched, and moreover that after this period has expired, the dry-plate has to be removed again from the heating unit. It is obvious that this renders the operation of the known driers very difficult, especially when color prints are to be dried which are very sensitive to overheating and react thereto in different manners, and may be easily damaged or completely ruined thereby.

It is an object of the present invention to provide a print drier which overcomes the above-mentioned disadvantages of the previous driers and especially permits the drying cloth to be tightened upon the dry-plate before the latter is applied upon the surface of the heating unit.

According to the invention, this object is attained generally by providing a supporting frame in which the dryplate is mounted, by pivotably connecting the clamping frame together with the drying cloth to this supporting frame, by providing means for locking the clamping frame to the supporting frame when the latter together with the drying cloth is pivoted upon the dry-plate, and by providing suitable means for applying the dry-plate together with the clamping frame and drying cloth upon the surface of the heating unit and for removing them therefrom.

The invention therefore provides the combination of the clamping frame with the dry-plate into a unit which may be applied upon and removed as a unit from the heating unit. This combination permits the drying cloth to be tightened upon the wet prints on the dry-plate at a place spaced from the heating unit and then to remain on the dry-plate during the entire drying process.

According .to one preferred embodiment of the invention, the supporting frame of the dry-plate is adapted to be lowered vertically upon the heating surface by being guided in a frame containing the heating unit, and to be hel-d under resilient tension in the lowered position, for example, by springs, so as to be automatically elevated from the heating surface when it is no longer positively held thereon. Thus, the danger is avoided that, when the operator is not available for .servicing the apparatus, the dry-plate might accidentally remain in its lowered position on the heating surface.

According to another preferred feature of the invention, the supporting frame is maintained in its operative position in which the dry-plate is pressed upon the heating surface by means of a locking device which may be automatically released by a time switch. This feature of the new print drier insures that the desired length of the drying period will be accurately maintained and that, after the drying operation is completed, the dry-plate together with the prints thereon will be automatically removed from the heating surface. The dried prints may then be taken off the dry-plate whenever the operator has the time to do so, and there is no danger that they will be harmed by remaining too long on the dry-plate after the latter is removed from the heating surface.

Another important feature of the invention consists in providing the apparatus with a pressure roller which is rotatably mounted on a pair of carriages and is movable by the latter so as to roll entirely over the clamping frame and drrying cloth. There is thus no longer any need for any separate mechanical squeegee device or a hand-operated roller squeegee and it is merely necessary to actuate the crank or motor drive to roll the pressure roller 'over the drying cloth on the dry-plate in order to squeegee the wet prints properly upon the dry-plate.

Another feature of the invention consists in providing the new print drier with a foot pedal for pressing the supporting frame with the dry-plate against the action of the mentioned spring force upon the heating surface of the heating unit.

A further feature of the invention consists in mounting the supporting frame of the dry-plate on four posts which are guided in the main frame of the apparatus so as to be movable simultaneously in a direction vertical to the main frame so that the dry-plate Iwill always remain parallel to the heating surface.

According to another preferred embodiment of the invention, the supporting frame may, however, also be pivotably connected to a part of the main frame which is spaced from the heating surface and permits the supporting frame to be pivoted about an axis which extends parallel to the pivot axis of the clamping frame. Another feature of the invention which is applicable to this embodiment consists in mounting the heating unit so that the heating surface thereof extends at an inclined angle to be more easily accessible from the front of the drier and in mounting the supporting frame together with the dry-plate in a manner so that when the supporting frame is pivoted upwardly from the heating surface to its end position, it will extend substantially within a horizontal plane.

These and further features and advantages of the present invention will become more clearly apparent from the following detailed description thereof which is to be read with reference to the accompanying drawings, in which- FIGURE l shows a perspective side view of a print drier according to one embodiment of the invention; while FIGURE 2 shows a perspective side view of a print drier according to a modification of the invention.

The print drier according to the first embodiment of the invention as illustrated in FlGURE 1 essentially consists of a main frame 1, a heating unit ywith a heating surface 2, a dry-plate 3 with an upper mirror-finished surface, and a drying cloth 4 which may be tightly applied upon the glossy side of plate 3 by means of a clamping frame 5.

The glossy dry-plate 3 of this apparatus is mounted independently of the heating surface 2 by means of a supporting frame 6 on four posts 7 which are slidable in suitable guides 7b on frame 1 and vertically to the latter. Posts 7 which may be tubular are acted upon by springs 7a which may be mounted, for example, within the posts and the lower ends of which rest on the bottom of the main frame 1, thus tending to maintain the supporting frame 6 together with the dry-plate 3 in the upper position, as shown in FIGURE 1. The two front posts 7 are pivotably connected at their lower ends to the two arms 8 of a U-shaped bracket, the central part of which forms a pedal 9 in front of the apparatus while the free outer ends of arms 8 are pivotably connected at 10 to frame 1 and also to each other by a shaft 11, the rotary movements of which are transmitted by connecting rods 12 to a similar shaft 13 which is rotatably mounted at the rear part of frame 1 and the movements of which are transmitted by connecting rods 14 to the two rear posts 7. Thus, when pedal 9 is depressed, the front and rear posts 7 are simultaneously drawn downwardly, whereby the dry-plate 3 is likewise moved downwardly and pressed against the heating surface 2.

Pedal 9 is further connected to a time switch 15 by a movable member 15a projecting from the latter and engageable in a recess 15b in one of the posts 7 which causes the depressed pedal 9 together with the dry-plate 3 to remain in the lower end position against the action of the mentioned springs for the length of time to which the time switch 15 is set.

The clamping frame is pivotably connected at its rear end at 6a to the supporting frame 6 and may be pivoted downwardly, in which case this frame 5 will move over the sides of frame 6 and the drying cloth 4 will be pressed uniformly from above upon the dry-plate 3. When the dry-plate 3 together with the supporting frame 6 is moved downwardly, the clamping frame 5 together with the drying cloth 4 is also moved downwardly without interfering with the main frame 1 or any other parts of the apparatus.

Locking means are provided for the clamping frame 5 when in its lower position against the supporting frame 6. These locking means comprise the shaft 5b carrying the front handle 5a, the shaft 5b being pivotally mounted within the clamping frame 5 and supporting at one end, as shown in FIGURE l, a small lever 5c which is axed to the shaft and which is pivoted by means of a draw spring 5d toward the clamping frame 5 so that a stop 5e, provided at the handle 5a, strikes against a front shaft 6b of the supporting frame 6 upon the frame 5 being pivoted downwardly. However, if during the downward movement of frame 5, the handle 5a is swivelled slightly clockwise against the force of the draw spring 5d, the stop 5e can then be moved downward in front of shaft 6b and will swing upon release of handle 5a below shaft 6b in a counterclockwise direction until it reaches a stopping point properly below shaft 6b, thereby locking the clamping frame 5 to the supporting frame 6. In order to return the clamping frame to its upper position it is only necessary to slightly turn the handle 5c: in a clockwise direction so that the stop 5e will release the shaft 6b.

Posts 7 further carry guide rails 16 which extend along both sides of frame 1. On each of these guide rails 16, a carriage 17 is movable from a rear position behind frame 1 to a position near the front edge of the apparatus. These two carriages 1'7 also form the bearings of a pressure roller or squeegee 18 which extends transverse to the guide rails 16 and may by means of the carriages 17 be rolled forwardly over the dry-plate 3 and the drying cloth 4 thereon. Roller 18 is resiliently mounted in the carriages 17 in a manner not specifically shown so as to follow the contours ofdry-plate 3 when moved along the same and to be pressed by spring force against the drying cloth 4 and dry-plate 3. Carriages 17 may be moved back and forth by a belt drive 19, the front pulley of which may be driven by a crank 20 or an electric motor.

The heating surface 2 of the drier according to FIG- URE 1 forms the upper wall of a closed container 21 which may be supplied with water which may be heated and thermostatically controlled by conventional means, not shown.

In the operation of the print drier according to FIG- URE 1, the wet photographic prints are first applied face down upon the dry-plate 3 if they are to be glossy. The clamping frame 5 is then pivoted downwardly until it is automatically locked to the front edge of the supporting frame 6 of dry-plate 3 by the locking means 5b, 5c, 5d, 6b as previously described.

The operator of the drier then operates the crank 20 so that the squeegee 18 is rolled several times over the dry-plate 3 and the drying cloth 4 and the prints are pressed with the proper pressure upon the dry-plate. rIlhereafter the operator steps on the pedal 9 which, under t-he contro'l of movable member 15a and recess 15b, then remains in the depressed position for the period as set on the time switch 15 during which the dry-plate -3 together with the prints and the drying cloth `4 a-lso lremain in tig-ht engagement With the heating surface 2.

This completes the actual manipulation of the drier since when the required drying period has expired, the time switch 1'5 automatically releases the dry-plate 3 and permits it to elevate. Thus, there is no possibility that the prints might be overheated after being dried. The operator may therefore at any time suitable to him again loosen the clamping 'frame 5 from the supporting frame y6 and pivot `the frame 5 upwardly and toward t'he rear whenever he is ready to 4remove the dried prints from the apparatus.

The second embodiment of the print drier according to the invention, as illustrated in FIGURE 2 differs from the first primar-illy fby the fact that the supporting frame together with the dry-plate is not Inova-ble vertically to the heating 'surface on the frame of the apparatus so as to remain parallel thereto, ybut that it is pivotable relative t-o the heating surface. Otherwise, the construction of this drier is very similar to that as described with reference to FIGURE 1 and a detailed description thereof would therefore be superfluous. In order to show this similarity more clearly, all of those ipa'rts in FIGURE 2 which are similar to those in FIGURE 1 are identified by the salme reference numerals except that each of them has been increased by 100.

In the embodiment of the invention according to FIG- URE 2, the supporting frame 106 is, however, not mounted on posts which are movable in their longitudinal directions as in FIGURE 1, but it is mounted on a shaft 122 which is lconnected to the main frame 101 so as to be pivotable upwardly and downwardly. Shaft 122 extends parallel to the pivot axis 106a of the clamping frame and is spaced from the heating surface 102 of the drier. The pedal 109 accordingly acts through its two arms 108, the bearings 110 and 113, the rods 112, and the levers 114 upon a pair of vertical connecting rods 123, the upper ends of which are pivo-tably connected to central points of the opposite sides of the supporting frame 106.

From FIGURE 2 it may be clearly seen that, when the pedal 109 is depressed, the connecting rods 123 will be drawn downwardly, whereby the supporting frame will be pivoted downwardly about its axis, namely the shaft 122, toward the heating surface 102. This downward movement is opposed by the action of two tension springs 124, each of which is connected at one end to the main frame 101 and at the other end to a second arm 125 of the angular lever 114. The time switch 115 which is likewise mounted on the main frame 101 may act through a locking member 11551 upon the arm 108`of pedal 109 in such a manner that the pedal will be arrested in its depressed position until the period to which the time switch 115 has been set has expired.

The inclined design of the heating surface m2, as illustrated in FIGURE 2, has not only the advantage that when the dry-plate 103 is lifted off the heating surface 192 and then extends almost horizontally, it is more easily accessible for applying the prints 126 thereon, but it also insures that in the heating unit which may be filled, for example, `with glycol oil no air bubbles will remain underneath the wall forming the heating surface 102 which may interfere with a uniform heat transfer to the heating surta-ce. Such air bubbles which are hardly avoidable in the actual operation of such a drier will then move to the highest point of the heating unit, that is, to the upper right in FIGURE 2, from which they may be released through an air-vent pipe, not shown.

Although my invention has been' illustrated and described with reference to the preferred embodiments thereof, I wish to have it understood that it is in no way limited to the details of such embodiments, but is capable of numerous modifications Within the scope of the appended claims.

Having thus 'fully disclosed my invention, what I claim is:

1. A print drier comprising heating means having a stationary upper heating surface, a dry-plate Ifor drying photographic prints and the like thereon, a clamping frame pivotably connected to said dry-plate so as to be pivotable relative thereto, a drying cloth connected to said clamping frame, and means for raising and lowering said dry-plate together with said clamping frame and said drying cloth as a unit relative to said heating surface.

2. A print drier comprising heating means having a stationary upper heating surface, a dry-plate for drying photographic prints and the like thereon, a supporting frame surrounding and holding said dry-plate, a clamping frame pivotably connected to said supporting frame so as to be pivotable relative thereto, a drying cloth connected to said clamping frame, means for locking said clamping frame to said supporting frame when pivoted upon the same, and means for raising and lowering said supporting frame together with said dry-plate, said `clamping frame, and said drying cloth as a unit relative to said heating surface.

3. A print drier comprising a main frame, heating means having a stationary upper heating surface mounted within said frame, a dry-plate for drying photographic prints and the like thereon, a supporting frame surrounding and holding said dry-plate, a clamping frame pivotably connected to said supporting frame so as to be pivotable relative thereto, a drying cloth connected to said clamping frame, means for locking said clamping frame to said supporting frame when pivoted upon the same, means for guiding said supporting frame on said main frame lfor movement in a direction toward and away from said heating surface to permit said supporting frame together with said dry-plate, said clamping frame, and said drying cloth to be raised and lowered as a unit relative to said heating surface, means for lowering said unit to apply said dry-plate against said heating surface, and spring means for raising said unit when said lowering means are released.

4. A print drier as detined in claim 3, further comprising locking means for maintaining said unit in the lowered position, time control means, and means responsive to the operation of said time control means for releasing said locking means when a certain period of time required for drying said prints has expired.

5. A print drier as defined in claim 1, further comprising guide 'rails extending along two opposite sides of the drier, a pressure roller guided by said guide rails, means for mounting said guide rails so that said pressure roller will be located substantially within the same plane as the upper surface of said dry-plate at least when said unit is in the raised position, and means for mounting said pressure roller on said gu-ide rails so as to be rotatable about its axis and to be moved along said guide rails and to roll along and exert a uniform pressure upon said drying cloth on said dry-plate during its rolling movement.

6. A print drier as defined in claim 5, in which said mounting means for said pressure roller comprise a pair of carriages having Wheels for riding along said guide rails, and bearing means on said carriages for rotatably mounting said pressure roller on said carriages and between the same, and driving means for moving said carriages back and forth along said rails.

7. A print drier as defined in claim 2, in which said means for raising and lowering said unit comprise spring means tending to maintain said unit in the raised position, and a foot pedal for lowering said unit against the action of said spring means and for applying said dry-plate under pressure against said heating surface.

3. A print drier as defined in claim 3, in which said means for guiding said supporting frame on said main frame comprise four posts slidably mounted on said frame and projecting lupwardly therefrom and movable simultaneously and parallel to each other in directions vertical to said frame, said means for lowering said unit comprising foot-actuated means for drawing said four posts equally and simultaneously downwardly against the action of said spring means, said spring means acting upon said posts to elevate the same when said foot-actuated means are released.

9. A print drier as defined in claim 2, in which said means for raising and lowering said unit comprise means for connecting said supporting frame to said main frame so as to be pivotable relative to said heating surface about an axis extending parallel to the pivot axis of said clamping frame and spaced from said heating surface.

10. A print drier as defined in claim `9, in which said heating surface is inclined so that its front edge is disposed in a position lower than its rear edge, said supporting frame being pivotably connected to said main frame at the rear side thereof, said supporting frame and said dry-plate thereon extending substantially within a horizontal plane when pivoted to their highest position away from said heating surface.

References Cited by the Examiner UNITED STATES PATENTS 1,910,294 5/1933 Kaminski 34-143 2,477,603 8/ 1949 Hester 34-144 2,542,654 2/ 1951 Gadden 34-48 2,585,893 2/1952 Young 24-143 2,799,949 7/ 1957 Richman 34-143 3,072,774 l/ 1963 Larsen et al. 34-143 3,114,254 12/ 1963 Rose 34-41 FREDERICK L. MATTESON, JR., Primary Examiner. NORMAN YUDKOFF, Examiner.

F. E. DRUMMOND, Assistant Examiner. 

1. A PRINT DRIER COMPRISING HEATING MEANS HAVING A STATIONARY UPPER HEATING SURFACE, A DRY-PLATE FOR DRYING PHOTOGRAPHIC PRINTS AND THE LIKE THEREON, A CLAMPING FRAME PIVOTALLY CONNECTED TO SAID DRY-PLATE SO AS TO BE PIVOTABLE RELATIVE THERETO, A DRYING CLOTH CONNECTED TO SAID CLAMPING FRAME, AND MEANS FOR RAISING AND LOWERING SAID DRY-PLATE TOGETHER WITH SAID CLAMPING FRAME AND SAID DRYING CLOTH AS A UNIT RELATIVE TO SAID HEATING SURFACE. 